Connection of high-frequency alternators for radiosignaling



Jan. 925 1,524,646

- M. LATOUR CONNECTION OF HIGH FREQUENCY ALTERNATORS FOR RADIOSIGNALING Filed Dec. 5, 1923 INVENTOR M IUS moun BY 02 kw ATTORNEY High-Frequency Alternators for Radiosig- Patented Jan. 27, 1925.

UNITED STATES PATENT: OFFICE.

. namus na'roun, or rams, rmnon.

CQNNEGTION 'OF HIGH-FREQUENCY ALTERNATOBS FOB RADIOSIGNALING.

Application rue December 5, 1923.1 serial-reeves To all whom it may concern: 1

Be'it known that I, Mnnrns LATOUR, a citizen ofthe Republic of France, and resident of Paris, France, have invented certain new and useful-Improvements in Connect-ions of naling, of which the following is a specificacapacity 16 nee 'tion accompanied by drawings.

conformfrequency alternators 2 and 4 coupled together by auto-transformer 15 having a condenser 16 connected to its terminals.

It must first be remarked that, according to the spirit of the'construction described,

thetransformeror auto-transformer 15 is furnished with a magnetic circuit 17 of iron, preferably torus-shaped; the two halves of the winding 15 are moreover intercalated turn by turn so asto reduce'leakage between them; the compensation of maetic force corresponding to leakage is t ereby rendered unnecessary, .while the reactan'ce constituted by the assembly of coil 15, on the other hand, in virtue ofthepresence of iron, I

is made very hi h with the consequence that s tobe made only of minimum amount; I The direct current motors are coupled together in parallel by means of rings and 6. It is clear that this coupling in itself adapted for machines workmg at 50 to 100 periods is unable to insure'the cou hng of alternators of 15-30000 periods which they drive. Still, in case of thealternators falling out of'step, the chances of their being caused to come into step again :by automatic means are necessarily greater. Furthermore, the coming in phase of the alternators 1s facilitated by the preliminary synchronization of the driving motors. This arrangement also is f real and practical interest in the case whlre the connection in series of alternators is dealt with. r

The sets may, no matter what the partlcular circumstances, be started jointly without being coupled drawing illus- In the case of asynchronous motor, the

connections between the rings of the rotors will evidently be established in a similar manner. j Y

To insure balanced load conditions between the motors, in the caseof both direct currentand alternating current it isfeasible toarrange the motors in series;xbut.inthe 7 particular case of direct I current, recourse may be had to an inductance coil 7 with two windings 8 and 9. "The production of an effective ma netic flux, in the case where the currents ta en by the motorsshould fail to be equal, is opposed'to the production differences in the value of the currents taken by the motors during control (key operation).

In French patent application No. 160,777,

dated June 19, 1922, entitled Improvements in speed regulation of high frequency generating sets for wireless telegraph it has been pointed out that, in order to keep the speed of one high frequency 'set'constant during control (key operation), agood plan is to provide a resistance in the armature circuit of the driving motor, and to short-circuit the same at the same. time where load is being put on the high frequency alternator.

Apart'from this, per se, novel arran ement,

it has been indicated in the same app 'cation for Letters Patent that, in order to obtain instantaneous variations ofv current in the armature of the motor, it is convenient to have recourse to mutual induction.

In the figure an arrangement is shown which eliminates the two actions. An ohmic (non-inductive) resistance 10 is arranged in.

series' with an induction coil 11 comprising twowindings 12 and 13. A11 operafing ke 14 short-circuits resistance 10 in series wit .the winding 12 at the very instant where load is put on the alternator. At no-load windings 12 and 13 are traversed by the current taken by the motor when idling. In the presence of load, only winding 13 is traver'sed bythe current taken by the motor when carrying a load. One may proceed in a way such that the flux in inductance coil 11 has the same value whether there is-no load or whether there is a load. Under these conditions, it is evident that the instantaneous establishment of stable or normal working conditions is romoted,

The compensation of the load of the motor by synchronous control or manipulation brought to act 11- on the armature current has been foun more efiective than the well-known action upon the field current,

with an inductance consisting of two windings which works a constant flux for both the no-load and the load operating state of the condenser (an arrangement based upon the invention described in the application for the above-cited patent) applies equally to the case where synchronous action is brought either upon the field circuit of the motor, or upon the exciting circuit of the generator which feeds the motors, or else upon the direct current of a'magnetic amplifier or a system of magnetic amplifiers in the case of drive by alternating current.

Having described my invention, what I claim is:

1. In a si naling system, the combination of a air 0? alternators adapted to be operate in parallel, a pair of motors connected in arallel for driving thev same, means for alancing the currents of said driving motors, comprising a self-induct-. ance coil connected 'at opposite ends to said motors and at an intermediate point to one of the supply lines for said motors, means for compensating the changes in load of said alternators comprising a circuit including a resistance and a self-inductance, said inductance being arranged to operate at constant flux regardless of load conditions and means for short-circuiting said resistance and a portion of said inductance.

2. In a signaling system, the combination of a pair of alternators adapted to be operated in parallel, a pair of motors connected in parallel for driving the same,

means for balancing the currents of said driving motors comprising a self-inductance coil connected at opposite ends to said motors and at an intermediate point to one of the supply lines for said motors, means for compensating the changes in load of said alternators comprising a resistance and an inductance in series with said supply line, said inductance being arranged to have a constant flux independent of load conditions and means for short-circuiting said resistance and a portion of said inductance.

3. In a radio signaling system, the combination of an antenna, a pair of alternators for energizing the same, said alternators being connected together through a coil having a magnetic core, said antenna being connected to the mid-point of said coil, a

pair of motors for driving said alternators, said motors being arranged for parallel operation, means for balancing load current between said motors comprising a self-inductance coil having opposite ends connected to said motors and an intermediate point connected to means for compensating load of said alternator, said means comprising a resistance and an inductance in series, said inductance being arranged to operate at constant flux and means for short-circuiting said resistance and a portion of said inductance synchronously wlth changes of load. a

US LATOUR. 

